used infrequently in the colloquial dialect. Pires and Rothaman use the expression, "missing-input competence divergence," to refer to instances when a grammatical property is missing from the colloquial variety. The dramatic difference between standard and colloquial dialects is particularly evident in cases of verbal morphology, the clitic system, the subjunctive, and inflected infinitives in Brazilian Portuguese. Pires and Rothman (2009) found that Brazilian Portuguese heritage learners do not acquire inflected infinitives because their input does not "robustly instantiate these forms". Similarly, Dominguez (2009) found that deviations in the use and distribution of indicative and subjunctive forms that were in the output of heritage Spanish speakers were also found in the children's input (parental speech). In certain cases, heritage language learners receive their input from first-generation migrants who have shown effects of attrition in certain domains. Consequently, the language learner would be missing grammatical properties in their input as a result of the interlocutor's attrition and would replicate these errors in their output. Pires and Rothman (2009) claim that due to their "inborn faculty of language," children automatically acquire the grammar found in their input. Therefore, in conclusion, it is not a deficient ability to acquire the language, but rather, the absence of, or limited access to, certain properties in the child's input that leads to errors in language production. Without access to a standard dialect of the target language often found in formal academic contexts, heritage language learners continue to make these production errors. Quantity of Input Heritage language learners may also have a smaller quantity of input than their monolingual peers because the heritage language is only found in a restricted number of contexts and with fewer interlocutors. Citing statistics found in studies on hearing children with deaf parents, Flores and Barbosa (2014) posit that bilingual heritage language learners need a minimum of 5 to 10 hours of interaction per week with the language to develop native-like proficiency. Hours of input may be particularly restricted once the heritage speaker switches to the dominant language. Cross-linguistic influence Cross-linguistic influence may contribute to heritage speakers' competence divergence. Heritage language learners show a tendency to overuse grammatical properties that are found in both the heritage language and the dominant language. Furthermore, heritage language learners may prefer grammatical structures from the dominant language and transfer them into the heritage language. To learn more about language transfer in bilingual individuals, see Crosslinguistic influence. Identity